There are many applications for optical detectors, that is detectors which can convert an optical image into an electrical analog of the optical image. Examples of systems which can utilize such detectors are surveillance devices, Fourier optics systems and data processing systems.
Conventional detectors or detector arrays used in these systems are exemplified by U.S. Pat. Nos. 2,880,119 and 2,884,507. Both of these patents disclose a photoconductive device or photocell in which a layer of photosensitizable material is deposited on an insulative base or substrate. The sensitized material is associated with a pair of electrodes which sense the photo-variable resistance therebetween. While detectors of this type have enjoyed a small degree of success, their full potential has been limited due to artificial configuration restraints and associated manufacturing difficulties and costs. Heretofore it has not been possible to consistently produce detector arrays having a predictable, uniform electrical response over the entire array with the requisite sensitivity for sophisticated systems. Since the entire region between the electrodes is photosensitive, positioning of the electrodes has been critical to uniformity of the resistance therebetween.